Keating: The great divider: immigration?

Noor Mononutu, left, originally from Indonesia and now of Sterling, Va., and Ashraf Mokhtar, right, originally from Egypt and now of Reston, Va., celebrate during a naturalization ceremony at the Treasury Department in Washington. More than 7,800 people became U.S. citizens at more than 100 special ceremonies across the country and around the world from July 1 to 5 (July 3, 2013). Photo Credit: Getty Images

WASHINGTON - Opponents of immigration reform in the United States argue that an influx of low-paid foreign workers will weaken the U.S. economy. But Matthew Sanderson has a different worry: Immigration may be too beneficial for the United States and other rich countries.

A recent study by the Kansas State University sociologist looks at how immigration affects global inequality. Sanderson found that wealthier countries benefited disproportionately. In fact, rich countries see their per capita incomes increase due to immigration up to 18 times more than middle-income countries, which in turn benefit twice as much as low-income countries. In part, this may be because healthy, developed countries tend to be able to more effectively absorb immigrants into their economies and in turn benefit from the expanded pool of low-wage labor. Over time, this disparity could produce what sociologists call a "Matthew effect," referring to the biblical Gospel, which says, "For unto every one that hath shall be given, and he shall have abundance: but from him that hath not shall be taken even that which he hath." In other words, the rich get richer and the poor get poorer.

Does this mean immigration is bad? "Clearly for individuals, immigration is beneficial, or else it wouldn't happen," Sanderson says. "But at the national level the effects are a lot more mixed." His research doesn't account for the tens of billions of dollars in remittances that migrants send back to their home countries each year. However, it does suggest that maybe the political conversation about immigration should be less about how to protect rich countries from an influx of workers than about how to make sure poor countries don't get left behind.

Joshua Keating writes the War of Ideas blog for Foreign Policy magazine, where he is associate editor.